How to know if a map is a sub-map of another in Scala?

Question

I've two maps, and i need to know if all the elements in map1 are in map2 also. I think that using sets is a good idea but this doesn't work.

map1 = Map("provider" -> pepe, "consumer" -> pipo)
map2 = Map("provider" -> pepe, "consumer" -> pipo, "id" -> 1)

map1.toSet subsetOf map2.toSet

Possible duplicate of [In Scala, how to check if a Map contains all entries from another Map?](https://stackoverflow.com/questions/25189198/in-scala-how-to-check-if-a-map-contains-all-entries-from-another-map) — Mario Galic, May 09 '19 at 15:23
In what sense does it "not work" then? It returns `true` as expected. — Andrey Tyukin, May 09 '19 at 15:26
Scala will come up with strangest possible type signatures for those `toSet` results. — sarveshseri, May 10 '19 at 07:14

Krzysztof Atłasik · Accepted Answer · 2019-05-09T15:33:50.880

You haven't specified what is the type of pepe and pipo but let's assume they've got the same type and it's String. When you use map1.toSet it would create a set with inferred type Set[(String, String)]. Your other map contains also integer so type would be Set[(String, Any)]. So your code won't compile because types don't match. One way to solve it would be just specifying type:

map1.toSet[(String, Any)].subsetOf(map2.toSet)

How to know if a map is a sub-map of another in Scala?

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